The objectives of the proposed research are to document the changes in the rates of phospholipid synthesis and turnover during a synchronous cell cycle in Escherichia coli and to investigate the significance of these changes in the division process. Cells will be synchronized using both membrane elution and sucrose gradient centrifugation. Phospholipids will be monitored using 32P and 14C Acetate. Changes in the rates of phospholipid synthesis and turnover have been previously reported during the division of snake forms of E. coli. Changes in lipid metabolism have also been reported during cell division in eukaryotic cell systems (activation of lymphocytes, relief contact inhibition of fibroblasts, erythropoesis). The proposed investigations of E. coli as a model system will provide definitive new information regarding bacterial cell division which may also prove significant in higher systems.